Use kRenderClientId command line flag when starting a render process

content/renderer/render_thread_impl.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_RENDERER_RENDER_THREAD_IMPL_H_
 #define CONTENT_RENDERER_RENDER_THREAD_IMPL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 190 matching lines @@
   cc::SharedBitmapManager* GetSharedBitmapManager() override;
   void RegisterExtension(v8::Extension* extension) override;
   void ScheduleIdleHandler(int64_t initial_delay_ms) override;
   void IdleHandler() override;
   int64_t GetIdleNotificationDelayInMs() const override;
   void SetIdleNotificationDelayInMs(
       int64_t idle_notification_delay_in_ms) override;
   int PostTaskToAllWebWorkers(const base::Closure& closure) override;
   bool ResolveProxy(const GURL& url, std::string* proxy_list) override;
   base::WaitableEvent* GetShutdownEvent() override;
+  int32_t GetClientId() override;
 
   // IPC::Listener implementation via ChildThreadImpl:
   void OnAssociatedInterfaceRequest(
       const std::string& name,
       mojo::ScopedInterfaceEndpointHandle handle) override;
 
   // CompositorDependencies implementation.
   bool IsGpuRasterizationForced() override;
   bool IsGpuRasterizationEnabled() override;
   bool IsAsyncWorkerContextEnabled() override;
@@ skipping 514 matching lines @@
   AssociatedInterfaceRegistryImpl associated_interfaces_;
 
   mojo::AssociatedBinding<mojom::Renderer> renderer_binding_;
 
   mojom::RenderFrameMessageFilterAssociatedPtr render_frame_message_filter_;
   mojom::RenderMessageFilterAssociatedPtr render_message_filter_;
 
   base::CancelableClosure record_purge_suspend_metric_closure_;
   bool is_renderer_suspended_;
 
+  int32_t client_id_;
+
   DISALLOW_COPY_AND_ASSIGN(RenderThreadImpl);
 };
 
 #if defined(COMPILER_MSVC)
 #pragma warning(pop)
 #endif
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_RENDER_THREAD_IMPL_H_